I will not upgrade my diesel to another one when the time comes if there continue to be offerings like the 7.3 gasser available. We have many newer diesel trucks in our fleet at work and the DPF and DEF systems continue to be a headache along with fuel pumps blowing up. Waiting for other trucks to regen is a pain. Diesel has become a much more difficult choice because of all the emissions stuff. A simpler and less maintenance intensive engine would be optimal for me since I will be retired soon. It may be a long while before my 6.0 dies, especially after all the work I have put into it, but I see the body of my 2006/200K F350 slowly deteriorating and know there are fewer miles left each year. I love my truck and I used to think a rebuild would be okay but the body may leave me no choice.
Purchasing a new truck would allow me to move to a dually and larger camper at about the same time I retire. This would suit my anticipated camping schedule. Watch me get whacked by a meteorite on my last day of work : )